• Title/Summary/Keyword: Energy Standard

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Assessment of RANS Models for 3-D Flow Analysis of SMART

  • Chun Kun Ho;Hwang Young Dong;Yoon Han Young;Kim Hee Chul;Zee Sung Quun
    • Nuclear Engineering and Technology
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    • v.36 no.3
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    • pp.248-262
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    • 2004
  • Turbulence models are separately assessed for a three dimensional thermal-hydraulic analysis of the integral reactor SMART. Seven models (mixing length, k-l, standard $k-{\epsilon},\;k-{\epsilon}-f{\mu},\;k-{\epsilon}-v2$, RRSM, and ERRSM) are investigated for flat plate channel flow, rotating channel flow, and square sectioned U-bend duct flow. The results of these models are compared to the DNS data and experiment data. The results are assessed in terms of many aspects such as economical efficiency, accuracy, theorization, and applicability. The standard $k-{\epsilon}$ model (high Reynolds model), the $k-{\epsilon}-v2$ model, and the ERRSM (low Reynolds models) are selected from the assessment results. The standard $k-{\epsilon}$ model using small grid numbers predicts the channel flow with higher accuracy in comparison with the other eddy viscosity models in the logarithmic layer. The elliptic-relaxation type models, $k-{\epsilon}-v2$, and ERRSM have the advantage of application to complex geometries and show good prediction for near wall flows.

Lightweight Energy IoT Standard Protocol and Test Certification Procedure (에너지 IoT 표준 프로토콜 경량화 및 시험인증절차에 관한 연구)

  • Park, Myunghye;Kim, Younghyun;Myoung, Nogil;Kang, Sukyung;Eun, Changsoo
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.2
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    • pp.129-135
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    • 2020
  • The standardization of e-IoT (energy Internet of Things) communication and service, which is the energy field of energy, is to define the standard model and to demonstrate the practical model in order to take the lead and occupy the market where new market is created with the latest technology. In particular, detailed technical specifications are defined for developing a framework for IoT technology, the foundation technology of the 4th Industrial Revolution, securing interoperability through standardization, and operating a standard platform. In this paper, we propose a method for e-IoT standard protocol lightening and test certification procedure. The proposed method provides a product implementation method that can solve the problem of low power issue of e-IoT product in the future.

Development Strategy of the Renewable Energy Industry through Improvement of Renewable Portfolio Standard : Focused on Photovoltaic and Wind (의무할당제도 개선을 통한 신재생에너지 산업의 발전 전략 : 태양광, 풍력에너지 중심)

  • Kim, Jongwoan;Park, Sangchul
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.110-123
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    • 2016
  • Since increase in energy consumption and environmental issues started to grab global attention, various countries have had their own supporting policy to promote supply of renewable energy which is a stable and eco-friendly energy source. This study analyses Korean Renewable Portfolio Standard by comparative analysis of current policies in major countries in respect of design components of a pragmatic industrial policy system, such as political leadership, policy coordination and consultative committee discussion, and policy enforcement with responsibility and transparency. This is to identify problems and to present political suggestions for successful management of the standard based on a fundamental concept of the pragmatism industrial policy. It is predicted that the strategic cooperation between a market and a government leads to industry development as the relationships of two parties are regarded not as antagonistic but as complementary.

Study on Characteristics of Dose Distribution in Tissue of High Energy Electron Beam for Radiation Therapy (방사선 치료용 고에너지 전자선의 조직 내 선량분포 특성에 관한 연구)

  • Na, Soo-Kyung
    • The Journal of Korean Society for Radiation Therapy
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    • v.14 no.1
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    • pp.175-186
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    • 2002
  • The purpose of this study is directly measure and evaluate about absorbed dose change according to nominal energy and electron cone or medical accelerator on isodose curve, percentage depth dose, contaminated X-ray, inhomogeneous tissue, oblique surface and irradiation on intracavitary that electron beam with high energy distributed in tissue, and it settled standard data of hish energy electron beam treatment, and offer to exactly data for new dote distribution modeling study based on experimental resuls and theory. Electron beam with hish energy of $6{\sim}20$ MeV is used that generated from medical linear accelerator (Clinac 2100C/D, Varian) for the experiment, andwater phantom and Farmer chamber md Markus chamber und for absorbe d dose measurement of electron beam, and standard absorbed dose is calculated by standard measurements of International Atomic Energy Agency(IAEA) TRS 277. Dose analyzer (700i dose distribution analyzer, Wellhofer), film (X-OmatV, Kodak), external cone, intracavitary cone, cork, animal compact bone and air were used for don distribution measurement. As the results of absorbed dose ratio increased while irradiation field was increased, it appeared maximum at some irradiation field size and decreased though irradiation field size was more increased, and it decreased greatly while energy of electron beam was increased, and scattered dose on wall of electron cone was the cause. In percentage depth dose curve of electron beam, Effective depth dose(R80) for nominal energy of 6, 9, 12, 16 and 20 MeV are 1.85, 2.93, 4.07, 5.37 and 6.53 cm respectively, which seems to be one third of electron beam energy (MeV). Contaminated X-ray was generated from interaction between electron beam with high energy and material, and it was about $0.3{\sim}2.3\%$ of maximum dose and increased with increasing energy. Change of depth dose ratio of electron beam was compared with theory by Monte Carlo simulation, and calculation and measured value by Pencil beam model reciprocally, and percentage depth dose and measured value by Pencil beam were agreed almost, however, there were a little lack on build up area and error increased in pendulum and multi treatment since there was no contaminated X-ray part. Percentage depth dose calculated by Monte Carlo simulation appeared to be less from all part except maximum dose area from the curve. The change of percentage depth dose by inhomogeneous tissue, maximum range after penetration the 1 cm bone was moved 1 cm toward to surface then polystyrene phantom. In case of 1 cm and 2 cm cork, it was moved 0.5 cm and 1 cm toward to depth, respectively. In case of air, practical range was extended toward depth without energy loss. Irradiation on intracavitary is using straight and beveled type cones of 2.5, 3.0, 3.5 $cm{\phi}$, and maximum and effective $80\%$ dose depth increases while electron beam energy and size of electron cone increase. In case of contaminated X-ray, as the energy increase, straight type cones were more highly appeared then beveled type. The output factor of intracavitary small field electron cone was $15{\sim}86\%$ of standard external electron cone($15{\times}15cm^2$) and straight type was slightly higher then beveled type.

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Voltage quality and Network Interconnection Standard Suitability in Jeju-Hangwon Wind Power Generation Farm (제주행원 풍력발전단지의 전압품질 및 연계기준 적합성 분석)

  • Kim, Se-Ho;Kim, Eel-Hwan;Huh, Jonhg-Chul
    • Journal of the Korean Solar Energy Society
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    • v.26 no.2
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    • pp.53-59
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    • 2006
  • The number of wind generation installations are growing substantially in Jeju, Korea. Many of these installations are significant in size and directly connected to the distribution system. Utility grid interconnection standards for interconnecting non-utility distributed generation systems are essential to both power system company and generation company. These interconnection standards are important to utilities, customers, wind generation manufactures and nation. In this paper, it is investigated the voltage quality and the suitability of Jeju-Hangwon wind power generation farm by network interconnection technology standard.

The Status and Analysis of PV Module's Certificate (결정질 태양전지모듈 인증시험 현황 및 분석)

  • Kim, Kyung-Soo;Kang, Gi-Hwan;Yu, Gwon-Jong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.55-55
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    • 2009
  • In this paper, we introduce the status of certificate test on crystalline silicon photovoltaic, module in Korea. Up to 5. 2009, about 200 models have passed certificate test under KS C IEC61215 standard. Most products are from Korea, Japan, China. And some are from USA, German and Taiwan. A few environmental test items' results and standard test methods will be discussed. The detail discussion will be shown in the following paper.

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Standard Weather Data of Seoul for Energy Simulation (에너지 시뮬레이션을 위한 서울의 표준 외기 온도 및 습도 데이터)

  • 김성실;김영일
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.11
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    • pp.897-906
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    • 2002
  • Standard temperature and absolute humidity weather correlations of Seoul for dynamic energy simulation have been developed regressing the measured data compiled by the Korea Meteorological Adminstration during a 10-year period from 1991 to 2000. The mathematical equations can generate the daily and yearly variations of outdoor weather data with consistency unlike the measured data which may show abnormal behavior, Considering that each hour of the day follows a certain yearly pattern, the correlations are developed for each hour. The derived 24 simple mathematical equations can be used for estimating outdoor temperature and humidity conditions for any arbitrary time of the year.